Maternal antibodies protect offspring from severe influenza infection and do not lead to detectable interference with subsequent offspring immunization

Abstract Background Various studies have shown that infants under the age of 6 months are especially vulnerable for complications due to influenza. Currently there are no vaccines licensed for use in this age group. Vaccination of pregnant women during the last trimester, recommended by the WHO as protective measure for this vulnerable female population, may provide protection of newborns at this early age. Although it has been observed that maternal vaccination can passively transfer protection, maternal antibodies could possibly also interfere with subsequent active vaccination of the offspring. Methods Using a mouse model, we evaluated in depth the ability of maternal influenza vaccination to protect offspring and the effect of maternal immunization on the subsequent influenza vaccination of the offspring. By varying the regimen of maternal immunization we explored the impact of different levels of maternal antibodies on the longevity of these antibodies in their progeny. We subsequently assessed to what extent maternal antibodies can mediate direct protection against influenza in their offspring, and whether these antibodies interfere with protection induced by active vaccination of the offspring. Results The number of immunizations of pregnant mice correlates to the level and longevity of maternal antibodies in the offspring. When these antibodies are present at time of influenza challenge they protect offspring against lethal influenza challenge, even in the absence of detectable HAI titers. Moreover, no detectable interference of passively-transferred maternal antibodies on the subsequent vaccination of the offspring was observed. Conclusion In the absence of a licensed influenza vaccine for young children, vaccination of pregnant women is a promising measure to provide protection of young infants against severe influenza infection

Pelvic lymph node dissection for cervical or bladder cancer: embedding residual fat tissue offers no added value

Diagnosis of lymph node metastases in pelvic lymph node dissection (PLND) is important for staging and treatment. Standard practice is to submit visible or palpable lymph nodes for histology. We assessed the added value of embedding all residual fatty tissue. Patients (n = 85) who underwent PLND for cervical (n = 50) or bladder cancer (n = 35) between 2017 and 2019 were included. Study approval was obtained (MEC-2022-0156, 18.03.2022, retrospectively registered). The median lymph node yield with conventional pathological dissection was 21 nodes (Interquartile range (IQR) 18–28). This led to discovery of positive lymph nodes in 17 (20%) patients. Extended pathological assessment found 7 (IQR 3-12) additional nodes, but did not result in identification of more node metastases. Histopathological analysis of residual fatty tissue harvested at PLND resulted in an increased lymph node yield, but not in the detection of additional lymph node metastases

Restrained expansion of the recall germinal center response as biomarker of protection for influenza vaccination in mice.

Correlates of protection (CoP) are invaluable for iterative vaccine design studies, especially in pursuit of complex vaccines such as a universal influenza vaccine (UFV) where a single antigen is optimized to elicit broad protection against many viral antigenic variants. Since broadly protective antibodies against influenza virus often exhibit mutational evidence of prolonged diversification, we studied germinal center (GC) kinetics in hemagglutinin (HA) immunized mice. Here we report that as early as 4 days after secondary immunization, the expansion of HA-specific GC B cells inversely correlated to protection against influenza virus challenge, induced by the antigen. In contrast, follicular T helper (TFH) cells did not expand differently after boost vaccination, suggestive of a B-cell intrinsic difference in activation and differentiation inferred by protective antigen properties. Importantly, differences in antigen dose only affected GC B-cell frequencies after primary immunization. The absence of accompanying differences in total anti-HA or epitope-specific antibody levels induced by vaccines of different efficacy suggests that the GC B-cell response upon revaccination represents an early and unique marker of protection that may significantly accelerate the pre-clinical phase of vaccine development